BEIJING—A wave of regulations aimed at cutting risk in China’s financial system is rippling through the country’s markets and sending banks and companies scrambling for funds.

During the past month, Chinese shares have fallen nearly 5%, draining almost half a trillion dollars out of the country’s markets. Bond yields have shot up to their highest levels in two years, and bond defaults hover at record levels. The uncertainty has also weighed on metals and commodity prices, already hurt by doubts around China’s growth momentum....